Each month in this column we highlight an in-house Web page of interest.
Send your suggestions to
bhenson@ucar.edu.

Comparing apples with apples: The Extreme Weather Sourcebook

Tornadoes cost Texas on average more than $40 million a year, while Iowa ranks first in costs of flooding, according to a new Web site launched by ESIG in February. The Extreme Weather Sourcebook provides quick access to data on the cost of damages from hurricanes, floods, and tornadoes in the United States and its territories. Decades of information are presented in constant 1997 dollars, simplifying comparisons among extreme-weather impacts and among states or regions.

"We created the site to spur investigation, because we're all affected by weather and climate," says ESIG's Roger Pielke, Jr., who led the project. The Sourcebook is also intended to be a user-friendly tool for journalists on deadline. "Users of information on weather impacts have been frustrated in the past by data in incompatible formats," says Roger. With the harmonized data on the new Web site, "people can compare apples with apples."

Visitors to the Sourcebook will find the states and U.S. territories ranked in order of economic losses from hurricanes, floods, tornadoes, and all three events combined. A dollar figure for the average annual cost in each category for each state is also provided. Links take the reader to graphs with more detailed information on cost per year for each state and each hazard. For those who want to dig deeper, there's a link to Roger's
Societal Aspects of Weather pages.

The data for hurricane impacts covers 1925-1995 (based on a study by Roger and NOAA's Christopher Landsea); for tornadoes, 1960-1994 (based on a database maintained by the NOAA Storm Prediction Center); and for floods, 1983-1996 (based on data published by the U.S. Army Corps of Engineers). The flood and tornado data were updated to 1997 dollar values using the Gross National Product Implicit Price Deflator, which is published annually by the White House. The hurricane data were normalized to 1997 values by adjusting for growth in population and wealth, in addition to inflation.

The site allows relative comparisons of where a region or state stands in the national picture. "This is quantitative information that should be used in a qualitative way," says Roger. He also warns that historical costs should not be used to predict what future damages might be: "The future could be very different."

The Sourcebook was partially funded by the U.S. Weather Research Program, which is focused on improving predictions and their use by decision makers (see the
cover story in this issue). See the
USWRP home page. Working with Roger to put together the Extreme Weather Sourcebook were ESIG Web expert Baat Enosh and former ESIG visitors Angel Gutierrez (Carleton College) and Miles Mercer (Florida State University). Zhenya Gallon